class="tags" href="/tags/ORACLE.html" title=oracle>oracleclass="tags" href="/tags/ShuJuKu.html" title=数据库>数据库启动的四个阶段c;见下图:
c="http://hi.csdn.net/attachment/201203/3/0_1330768197kfZ0.gif" alt="" />
1. class="tags" href="/tags/ShuJuKu.html" title=数据库>数据库处于SHUTDOWN状态
在此种状态c;class="tags" href="/tags/ShuJuKu.html" title=数据库>数据库处于停止状态。不能接受外界数据请求。使用操作系统命令ps –ef | grep ora看不到任何class="tags" href="/tags/ShuJuKu.html" title=数据库>数据库进程的存在。
2. class="tags" href="/tags/ShuJuKu.html" title=数据库>数据库处于NOMOUNT状态
在此种状态c;class="tags" href="/tags/ShuJuKu.html" title=数据库>数据库后台进程已经建立。并根据参数文件中关于SGA的相关参数c;建立共享内存区和缺省的class="tags" href="/tags/ORACLE.html" title=oracle>oracleclass="tags" href="/tags/ShuJuKu.html" title=数据库>数据库进程。并同时检查相关初始化参数的正确性。
使用操作系统命令可以考到相应的进程。ps –ef | grep ora_ 并且使用ipcs –m命令可以看到以class="tags" href="/tags/ORACLE.html" title=oracle>oracle用户建立起来的共享内存区。
class="tags" href="/tags/ORACLE.html" title=oracle>oracle@db1:~> class="tags" href="/tags/SQL.html" title=sql>sqlplus / as sysdba
SQL*Plus: Release 10.2.0.1.0 - Production on Sat Mar 3 22:48:27 2012
Copyright (c) 1982, 2005, Oracle. All rights reserved.
Connected to an idle instance.
SQL> startup nomount;
ORACLE instance started.
Total System Global Area 167772160 bytes
Fixed Size 1218316 bytes
Variable Size 104859892 bytes
Database Buffers 58720256 bytes
Redo Buffers 2973696 bytes
SQL>
查看进程状态.
class="tags" href="/tags/ORACLE.html" title=oracle>oracle@db1:~> ps -ef | grep ora_
class="tags" href="/tags/ORACLE.html" title=oracle>oracle 3626 1 0 22:48 ? 00:00:00 ora_pmon_orcl1
class="tags" href="/tags/ORACLE.html" title=oracle>oracle 3628 1 0 22:48 ? 00:00:00 ora_psp0_orcl1
class="tags" href="/tags/ORACLE.html" title=oracle>oracle 3630 1 0 22:48 ? 00:00:00 ora_mman_orcl1
class="tags" href="/tags/ORACLE.html" title=oracle>oracle 3632 1 0 22:48 ? 00:00:00 ora_dbw0_orcl1
class="tags" href="/tags/ORACLE.html" title=oracle>oracle 3634 1 0 22:48 ? 00:00:00 ora_lgwr_orcl1
class="tags" href="/tags/ORACLE.html" title=oracle>oracle 3636 1 0 22:48 ? 00:00:00 ora_ckpt_orcl1
class="tags" href="/tags/ORACLE.html" title=oracle>oracle 3638 1 0 22:48 ? 00:00:00 ora_smon_orcl1
class="tags" href="/tags/ORACLE.html" title=oracle>oracle 3640 1 0 22:48 ? 00:00:00 ora_reco_orcl1
class="tags" href="/tags/ORACLE.html" title=oracle>oracle 3642 1 0 22:48 ? 00:00:00 ora_cjq0_orcl1
class="tags" href="/tags/ORACLE.html" title=oracle>oracle 3644 1 0 22:48 ? 00:00:00 ora_mmon_orcl1
class="tags" href="/tags/ORACLE.html" title=oracle>oracle 3646 1 0 22:48 ? 00:00:00 ora_mmnl_orcl1
class="tags" href="/tags/ORACLE.html" title=oracle>oracle 3648 1 0 22:48 ? 00:00:00 ora_d000_orcl1
class="tags" href="/tags/ORACLE.html" title=oracle>oracle 3650 1 0 22:48 ? 00:00:00 ora_s000_orcl1
class="tags" href="/tags/ORACLE.html" title=oracle>oracle 3669 3652 0 22:50 pts/2 00:00:00 grep ora_
class="tags" href="/tags/ORACLE.html" title=oracle>oracle@db1:~>
class="tags" href="/tags/ORACLE.html" title=oracle>oracle@db1:~> ipcs -m
------ Shared Memory Segments --------
key shmid owner perms bytes nattch status
0xe835086c 458764 class="tags" href="/tags/ORACLE.html" title=oracle>oracle 640 171966464 14
class="tags" href="/tags/ORACLE.html" title=oracle>oracle@db1:~>
3. class="tags" href="/tags/ShuJuKu.html" title=数据库>数据库处于MOUNT状态
class="tags" href="/tags/ShuJuKu.html" title=数据库>数据库读取控制文件中的内容c;并按照控制文件中指定的参数找到相应的数据文件c;并启动class="tags" href="/tags/ShuJuKu.html" title=数据库>数据库的归档或非归档状态。
class="tags" href="/tags/ShuJuKu.html" title=数据库>数据库在此状态检查各个数据文件的一致性。如果出现数据文件损坏c;要求用户进行恢复。
SQL> startup mount;
ORACLE instance started.
Total System Global Area 167772160 bytes
Fixed Size 1218316 bytes
Variable Size 104859892 bytes
Database Buffers 58720256 bytes
Redo Buffers 2973696 bytes
Database mounted.
4. class="tags" href="/tags/ShuJuKu.html" title=数据库>数据库处于OPEN状态
class="tags" href="/tags/ShuJuKu.html" title=数据库>数据库在此状态检查各个数据文件的一致性。如果出现数据文件损坏c;要求用户进行恢复。
SQL> startup;
ORACLE instance started.
Total System Global Area 167772160 bytes
Fixed Size 1218316 bytes
Variable Size 104859892 bytes
Database Buffers 58720256 bytes
Redo Buffers 2973696 bytes
Database mounted.
Database opened.
SQL>
5.改变class="tags" href="/tags/ShuJuKu.html" title=数据库>数据库的状态
SQL> startup nomount;
ORACLE instance started.
Total System Global Area 167772160 bytes
Fixed Size 1218316 bytes
Variable Size 96471284 bytes
Database Buffers 67108864 bytes
Redo Buffers 2973696 bytes
SQL> alter class="tags" href="/tags/DATABASE.html" title=database>database mount;
Database altered.
SQL> alter class="tags" href="/tags/DATABASE.html" title=database>database open;
Database altered.